Update to this recent post
I was passing through Jedediah Smith Redwoods State Park last week and happened to have this prototype in the rental car. The scenes from the movie were shot in the area, so I could not resist making a quick video.
P in Cleanflight is at about 100 for roll if I remember correctly, which I believe is more than double the default. The more I think about this, the more I begin to suspect that it is because 10 degrees is way to much for the motors to be angled. I believe the high angle is just too aggressive, and that I can build a more efficient version with tamer gains if I reduce it. I am thinking about 5 degrees should be right, probably resulting in more stability as well.
Motors 1 and 3 yaw left, 2 and 4 yaw right, 2 and 3 roll left, 1 and 4 roll right.
Rotors that sit at a more level plane will also help a lot in creating coaxial/redundant/overlapping versions. I hope to have a new and improved version printed and tested out soon...
more info at electronflight.com